Heavy Duty (Walt Disney's Comics and Stories #537, 1988)
Daisy Duck holds a weight contest, in which the heaviest resident of Duckburg can win their weight in gold, courtesy of the Gobblemore Foundation. Upon mishearing a phone call, Donald Duck decides to gain weight just to win Daisy's affection, but only before mishearing again that he is just too heavy for her.
Unknown comic published in early 2000's in the polish "Kaczor Donald" magazine
In this comic, Donald fattens up a thief in order to escape from being held hostage by him.
Unknown comic published in the 2009 "Kaczor Donald" magazine
Gyro Gearloose invents the "Tastemat", a machine that can make everything taste good. This makes several residents of Duckburg fat.